Fewer than 10 women victims have come forward so far in the ever-widening investigation into nude photos of female service members that were posted online without their permission, the top Marine general said on Friday. And he pleaded with female Marines to "trust us" and reach out to make complaints or seek help.

"I need their help," Gen. Robert Neller, the Marine commandant, said. "I'm going to ask them to trust us. I understand why that might be a bit of a reach for them right now. But I can't fix this ... The only way there is going to be accountability in this is somebody comes forward and tells us what happened to them."

Former and current female Marines have said their photographs and those of women in other services were shared on social media without their consent. Nude photographs of female Marines, veterans from across the military, and other women were shared on the Facebook page "Marines United," and the accompanying posts included obscene and threatening comments.

The Naval Criminal Investigative Service launched an investigation into the matter and is urging victims of the photo-sharing to come forward.

NCIS says it has received numerous tips. The other services are looking into the matter, but say they aren't aware of other victims.

Speaking to Pentagon reporters, Neller expressed frustration and disgust at the nude-photo sharing. And he acknowledged that there are a lot of unanswered questions about what happened, how many people or Marines were involved, and what some of the legal parameters will be for punishing service members who posted or shared the photos or who made threatening comments about them.

He said the controversy has an effect on the entire Marine Corps and the investigation must be done carefully.

"We don't want to be in a hurry. We want to make sure we're thorough and we're within the law," Gen. Robert Neller told a Pentagon news conference.

"This affects our entire organization," the general said, noting that men and women Marines have been serving side-by-side at war for 15 years, many losing their lives. But there's a sense that women still aren't accepted by some members of the corps.

"So what do you gotta do to get in?" said Neller, staring into the line of cameras in the back of the room. "I mean, c'mon guys. They just want to do their job. Let them do their job. And you do yours."

Separately, officials said Defense Secretary Jim Mattis will meet military and civilian officials in coming days about the reports.

Mattis also issued a statement condemning the actions.

"The purported actions of civilian and military personnel on social media websites, including some associated with the Marines United group and possibly others, represent egregious violations of the fundamental values we uphold at the Department of Defense," Mattis said in a written statement.

Navy Capt. Jeff Davis, a Pentagon spokesman, said Friday that Mattis wants the services to take appropriate action.

Active-duty Marine Marisa Woytek and former Marine Erika Butner appeared at a news conference in Los Angeles on Wednesday to applaud the investigation.

Butner, 23, who served for four years before leaving the Marines in 2016, said she contacted investigators in January and told them there was an online storage drive that contained "indecent photos of women from all military services, organized by name, rank and even where they were stationed."

The women's lawyer, Gloria Allred, said there may be hundreds of such postings and that they prompted pornographic and violent replies, including some recommending that female Marines be raped or shot.

Victims can reach the NCIS by going to: http://www.ncis.navy.mil/ContactUs/Pages/ReportaCrime.aspx